The best I have found so far is straight DTS 5.1 using optical audio and split the L/R surround output myself fed to the surround and rear amps to give you psuedo 7.1.

You still get the excellent bass response that comes from optical DTS 5.1, and get spearation on left and right surround and rear channels.

There is a definate difference in quality, expectially the bass. Something gets lost in the processing of NEO and PLIIx

Is there a way to achieve this in software?